This proposal concerns how aging affects the chemical senses: taste, smell, and common chemical sense. (The latter registers the spicy, sharp components of substances like peppers, vinegar, salt, horseradish, spirits, and carbonated beverages.) Our past work leads to the hypothesis that aging dulls this sense and true smell profoundly -- far more than taste -- and that the widespread complaints of the elderly about the flat "taste" of food springs largely from the loss of nasal sensations normally "referred" to the mouth. We will extend our studies to cover a larger number of representative odorants and tastants, to a wider age span, to common chemical sensations aroused in the mouth, to direct matching comparisons of odor and taste, to refinement of methods used to compare sensation magnitudes in young and old, with attempts to streamline present methods for clinical evaluation. The primary method used is magnitude matching, a procedure designed in our laboratory to separate out true sensory losses from cognitive changes associated with aging, but we will supplement this with others, e.g., threshold measurements, questionnaires aimed at suggesting etiologies, and the measurement of a reflex apnea in response to nasal inhalation of common chemical stimuli. Finally, we will study a group of elderly subjects selected for chronic complaining about the flat taste of their food to learn whether the complaining has a basis in the chemical senses. The overall goal is to learn enough about the chemical senses in aging so as to suggest ways to improve the pleasure derived from eating for the elderly and by extension their nutritional state.